Special education and parental school choice are two of the most controversial issues in K-12 education in the United States. Those policies converge on an important question in an evaluation of the Milwaukee Parental Choice Program, what proportion of students have education-related disabilities? This debate has provoked a lawsuit against the state’s Department of Public Instruction (DPI), which implements the Milwaukee Parental Choice Program (MPCP), the oldest and largest urban private school voucher program in the United States.

We might expect the MPCP to serve fewer students with disabilities than Milwaukee Public Schools (MPS), since most federal disability laws do not apply to private schools and the MPCP schools do not receive any extra government funds to serve students with disabilities. Still, if only a small portion of all MPCP students have disabilities, that finding would raise questions regarding the extent to which the program is fulfilling its original mission to serve disadvantaged students in Milwaukee.

Based on evidence we have collected over five years of studying the MPCP, we are able to estimate that between 7.5 and 14.6 percent of Choice students have disabilities that likely would qualify them for special education services in MPS. We have access to three different sources of statistical evidence regarding the percentage of MPCP students who have disabilities. We find that: (1) 14.6 percent of the MPCP students we observed in both the private and public school sectors from 2006 through 2010 were classified as participating in special education while in MPS; (2) 7.5 percent of all MPCP students were classified as having disabilities when we used MPS administrator designations for students who spent any time in MPS and MPCP administrator designations for students who always remained in MPCP; and (3) 11.4 percent of MPCP students were described by their parents as having disabilities, based on responses to our parent surveys administered from 2007 through 2009. Our estimated rate of student disability in the MPCP is between 23 and 61 percent lower than the rate of student disability of 19 percent reported for MPS.

Additionally, we conducted site visits of 13 MPCP schools in part to learn about how they serve students with disabilities. What we observed during those visits confirmed claims in the research and policy literature that most private schools lack the incentives, personnel, protocols, and organizational culture that lead public school systems to label students with disabilities as requiring special education services. In many cases, private school personnel hesitate to count a student as having a disability, even if public school personnel would recognize the student as such. However, that does not mean that private schools do not enroll students who would be formally designated as students with special needs if they were in the public schools.